Amprobe GSD600 [3311832] Gas Leak Detector w/ Flexible Probe for Methane and Propane. The Amprobe GSD600 Gas Leak Detector is a fast responding gas leak detector for methane and propane gas. The meter emits a frequency tone when gas is detected. The frequency of the beep coincides with the concentration of the gas. The LEDs display the level of gas present in an area or room. Pinpoint gas leaks for closed piping systems. Use the mute function in quiet work areas and utilize the LED displays. Or a standard earphone jack for hearing the meter in loud environments.